Automotive transmission



Du?, 1937, PQ l.. TENNEY M3365 AUTOMOTIVE TRANSMISSION Filed Jan. 22, 1934 1w la Will/'7111111 Patented Dec. 7, 1937 unirse STATES AUTOMOTIVE TRANSMISSION Perry L. Tenney, Lansing, Mich.,V assigner to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application January 22, 1934, Serial No. 707,663

4 Claims.

This inventionrelates to power Vtransmission andhas been designed for use on motor vehicles to provide a plurality of driving ratios.

An object of the inventionis to simplify the 5 assembly of gears in a housing to the end of reducing the cost of manufacture.

Another object is to provide va construction wherein conventional shiftingrods between the shift lever and sliding gears may be omitted.

Other objects and advantages will be understood from the following description.

In the drawing:

Fig. 1 is a longitudinal section of the transmission assembly.

Fig. 2 is a section on line 2-2 of Fig. 1. Fig. 3 is a section on line 3 3 of Fig. 1.

Fig. 4 shows a detent device in perspective.

Referring by reference characters to the drawing, numeral 5 is a gear housing. The top of the housing as at -1 is formed Vas an integral part thereof, not separable as is the usual practice. `It has an opening at 9 to receive the shift lever Il, the latter being inserted from `above through the opening 9 as will be seen. A pivot pin I3 is passed through openings in the top part 1 and is secured `as shown in Fig. 2. 'it pivotally supports shift members I5 and I1. The pin is tapered as at I9 from its mid portion for a little way toward each end. The lever I I encompasses these tapered regions to permit transverse tilting between the members I5 and I1. Circular springs '2| are located in grooves 23 in opposite faces of lever Il, one end of each spring being inserted in a transverse opening in the lever as shown by Fig. 2. The springs resiliently position the lever and prevent rattling. The lower end of the lever II has recesses25, 21 `to receive therein intermediate parts of the one or the other of members I5 and I1 when the lever is transversely shifted. After being so lengaged a longitudinal rocking movement of the lever will similarly rock the engaged member to effect gear movements for ratio changing. The lever end passes through an interlocking plate 29 guided by pins 3| carried by the housing for permitting transverse movement only. These pins engage the walls of slots 33 as shown by Fig. 3. The plate 29 has van opening with notches 31 for receiving that one'of the members (I1 in Fig. 3) not engaged by the lever II. The member locked by plate 29 is held from longitudinal movement, but the other member, freed from locking engagement by the transverse movement of plate 29 and the lever il, may be rocked longitudinally about its rotary support on pin I3. The dimension, longitudinally, of the opening in plate 29 and the shape of the lower end of lever II are designed to permit the above movements.

The transmission housing 5 has a single removable cover 39 through vvhich passes the input shaft 4I. A suitable bearing t3 is provided therefor, the outer race of which is held against a shoulder 45 in the cover by a retaining ring 111 and the inner race of which is held against a shoulder of shaft 4I by a threaded ring 49. Through the other end of the housing projects a driven or output shaft 5I carrying a coupling member 53 splined thereto and held axially by a nut 55. The member 53 may be equipped with a pinion 51 to drive a gear 59 on a shaft 6I mounted in casing 5. This is for connection with a speedometer. Inwardly of the speedometer drive gearing is a bearing 63 between the housing 5 Vand shaft 5I. At its front end the shaft 5I is piloted into a recessed end of input shaft lli as usual.

A v'I'he output shaft is formed with helical splines 65 for helical gears 61 and 69 whereby the gears may be reciprocated on the splines. Internally, gears 61 and 69 have channels to receive resilient detent locking rings 1I one of such rings being shown in perspective in Fig. 4. The splines on shaft 65 are provided with grooves 13 into which the rings 1I snap as the gears are reciprocated to positions according to neutral or predetermined gear ratios. The members I5 and l1 engage collars 14 and 15 on gears 61 and 69. Gear 61 is also formedwith clutch teeth 11 to engage internal teeth 19 on the end of input shaft 4I. A spool-like countershaft 8l with helical gears 83, 85, 81 and 89 is rotatable on spindle 9i projected through openings therefor in the housing and secured by fastening means 93. As usual a `reverse idler indicated by numeral 95 meshes with gear B9.

Helical gear 91 on the input shaft 4I is in oonstant driving engagement with the gear 83 on the countershaft. For direct driving clutch 11 is moved into mesh with teeth 19 by forward reciprocation of gear 61. Rearward reciprocation of 61 brings it into mesh with countershaft gear 85 for second speed driving. For low speed, gear 59 is moved forward into mesh with countershaft gear 81 and for reverse, gear 69 is moved to engage gear which is in constant engagement with gear 89. The helical splines cooperate with the helical teeth to facilitate gear meshing.

One important feature of the invention resides in the simplicity of the housing and its low cost of production made possible by the manner in which the parts are to be assembled. The countershaft spool may be inserted through the opening normally closed by cover 39. When dropped into position the spindle 9| is extended through the spool and secured in position. 'I'he reverse idler is also assembled by insertion through the front opening. The output shaft 5I with member 53 may be projected forwardly through the rear housing opening and the gears 69 and 61 previously passed through the front opening are slipped upon the splines of the shaft. When the members I5 and I'l and the lever II have been projected through the opening 9 and the members engaged with the collars of the gears, the pin I3 may be assembled through the openings of the fork and lever and secured in position. The input shaft after assembly with the cover 39 may be projected into the front opening, its gear 9'! moved into mesh with gear 83 and the recessed end of the shaft engaged With the reduced end of yshaft 5I. The securing of the cover completes the assembly. Preferably the lever II may carry a cup-shaped protecting cover` 99.

I claim:

l. In combination, a transmission housing, movable power-transmitting ratio changing members in said housing, a pivot pin extended transversely of and Within said housing, shift elements rotatably supported on said pin and engaging said members, a manually operable lever mounted on said pin for both longitudinal and transverse rocking movements, said lever having parts to engage the one or the other of said elements by its transverse movements and to thereafter rock said engaged element by its longitudinal rocking movement.

2. In combination, a transmission housing, movable ratio changing members in said housing, a pivot pin extended transversely and within said housing, shift elements rotatably supported on said pin and engaging said members, a manually operable lever mounted on said pin for both longitudinal and transverse rocking movements, said lever having parts to engage the one or the other of said elements by its transverse movements and to thereafter rock said engaged element by its longitudinal rocking movement together with an interlocking plate, means to restrict said plate tok transverse movements only, said plate having a slot, the walls of said slot engaged by said manually operable lever whereby said plate is transversely shifted by transverse rocking of said lever, said slot shaped to lock the element released from engagement with the lever.

3. In a change speed mechanism for vehicles including a housing and axially movable powertransmitting members therewithin, an actuating sub-assembly comprising elements engageable with said members and a shift lever, a common fulcrum pin for said lever and elements, said pin being mounted within and transversely of said housing.

4. In a change speed mechanism for vehicles including a housing and axially movable members therewithin, an actuating sub-assembly comprising elements engageable with said members and a shift lever, a common fulcrum pin for said lever and elements, said pin being mounted Within and transversely of said housing, there being two of said elements, the shift lever being fulcrumed between said elements on said fulcrum pin and shaped to rock transversely to engage the one or the other of said elements, together with an interlocking plate, means to mount said plate for transverse movement by like movements only, said interlocking plate and shift lever having engaging parts whereby the shift lever in its transverse movements may move the locking plate, said plate adapted When so moved to engage and lock one of said elements from longitudinal movement.

PERRY L. TENNEY. 

